Slot antenna device and wireless apparatus employing the antenna device

Abstract

A miniaturized and thin slot antenna device maintains high transmitting and receiving performance by improving the configuration of an antenna body and a circuit substrate. The slot antenna device includes an antenna body made of an electrically conductive member having a slot into which the circuit substrate is placed. Alternatively, the slotted, electrically conductive member can be placed flat on a first surface of the circuit substrate, which can contain a reflector on its second, opposite surface. The slot antenna device also can be constructed from two parallel, opposed, electrically conductive members spaced apart by a gap so that a slot is defined by outer peripheries of the electrically conductive members. The electrically conductive members can be provided on opposite surfaces of a circuit substrate.

What is claimed is: 
     
       1. A slot antenna device comprising: a slot antenna body including an electrically conductive member having a slot, the electrically conductive member including one continuous portion that defines a slot radiator, said continuous portion including feeding points positioned such that the slot radiator is interposed therebetween; and   a circuit substrate containing a wireless apparatus circuit, said circuit substrate extending through said slot in said electrically conductive member, said wireless apparatus circuit coupled to said electrically conductive member.   
     
     
       2. A slot antenna device according to claim 1, wherein said wireless apparatus circuit includes a circuit for transmitting signals. 
     
     
       3. A slot antenna device according to claim 1, wherein said wireless apparatus circuit includes a circuit for receiving signals. 
     
     
       4. A slot antenna device according to claim 1, wherein said circuit substrate is a circuit board. 
     
     
       5. A slot antenna device according to claim 1, wherein said electrically conductive member is a metal plate. 
     
     
       6. A slot antenna device according to claim 1, wherein said electrically conductive member has at least one bend that intersects said slot so that said slot faces in at least two directions. 
     
     
       7. A slot antenna device according to claim 6, wherein said electrically conductive member has a plurality of said bends, each bend intersecting said slot so that said slot faces in at least three directions. 
     
     
       8. A slot antenna device according to claim 7, wherein said electrically conductive member has four of said bends, each bend intersecting said slot so that said electrically conductive plate has a rectangular shape and said slot faces in four directions. 
     
     
       9. A slot antenna device according to claim 1, wherein said electrically conductive member has, on opposed sides of said slot, a first feed point attached to terminals of said wireless apparatus circuit to define an unbalanced circuit, and a second feed point attached to a ground terminal of said wireless apparatus circuit. 
     
     
       10. A slot antenna device according to claim 1, wherein said electrically conductive member has, on opposed sides of said slot, a feed point attached to two terminals of a balanced circuit of said wireless apparatus circuit. 
     
     
       11. A wireless apparatus comprising: a slot antenna circuit;   a connection circuit coupled to said slot antenna circuit;   an amplification circuit coupled to said connection circuit;   a demodulating circuit coupled to said amplification circuit;   said slot antenna circuit including: a slot antenna body including an electrically conducting member having a slot, the electrically conductive member including one continuous portion that defines a slot radiator, said continuous portion including feeding points positioned such that the slot radiator is interposed therebetween; and   a circuit substrate containing said connection circuit, said amplification circuit, and said demodulating circuit, said circuit substrate extending through said slot in said electrically conductive member, said connection circuit coupled to said electrically conductive member.